Crown Endo Treated Teeth-Dr. Serag Flashcards
(37 cards)
1
Q
What is the purpose of adding a Post to endo teeth?
A
- Only helps retain the core
- DOES NOT strengthen the tooth
2
Q
Why are endo treated teeth different?
A
- Loss of Sensation
- Physical Properties
- Loss of Structural integrity
3
Q
Loss of sensation
A
- No protective feedback to pain
- Maintain proprioception ONLY
- sense of position and movement
4
Q
Altered Physical Properties
A
- Loss of hydration/moisture
- no effect on physical properties
- Reduced strength
- slight reduction in hardness
- Mechanical properties
- no reduction
5
Q
Loss of Structural Integrity
A
- Due to loss of tooth structure from
- caries
- fracture
- endo procedure
- Have greater possibility to fracture
- reduced stiffness
- main reason why endo teeth are weakened
6
Q
What are 2 factors to consider when restoring an endo treated tooth?
A
- Functional load on the tooth
- Remaining tooth structure
7
Q
Tx Planning :Functional Load on the tooth
A
- tooth position
- anterior or posterior
- Single crown or RPD or FPD abutment
- Opposing dentition
- natural tooth vs removable prosthesis
- Parafunctional habits
- bruxism
8
Q
Tx Planning: Remaining tooth structure
A
- Class 1:
- most favorable prognosis
- remaining tooth structure is enough to support crown w/o post
- Class 2:
- more loss of coronal tooth structure
- needs post to retain core
- Class 3:
- significant loss of coronal tooth structure
9
Q
Anterior Teeth Treatment Options
minimal vs significant coronal damage
A
- Minimal Coronal Damage
- Intact tooth (except small access opening)
- greater strength against fractures
- or small proximal lesions/restorations
- Tx: simple direct restoration
- Intact tooth (except small access opening)
- Significant Coronal damage
- Extensive coronal destruction
- large proximal caries/restorations and unsupported enamel
- Tx:
- Post & Core and Crown
- Extensive coronal destruction
10
Q
Anterior Teeth Treatment Options
minimal vs significant coronal damage
A
- Minimal Coronal Damage
- Intact tooth (except small access opening)
- greater strength against fractures
- or small proximal lesions/restorations
- Tx: simple direct restoration
- Intact tooth (except small access opening)
- Significant Coronal damage
- Extensive coronal destruction
- large proximal caries/restorations and unsupported enamel
- Tx:
- Post & Core and Crown
- Extensive coronal destruction
11
Q
Posterior Teeth Treatment Options
minimal vs significant coronal damage
A
- if not crowned, significant increase in mechanical failure
- Minimal coronal damage
- intact tooth
- small access opening
- Tx:
- crown after sealing access hole (Different than anterior)
- intact tooth
- Significant Coronal Damage:
- Extensive coronal destruction
- large proximal caries/restorations and unsupported enamel
- Tx: Post & Core and crown (same as anterior)
- Extensive coronal destruction
12
Q
Ferrule Effect: Define
A
- height of tooth structure from core margin to crown margin
13
Q
What is the latin meaning of Ferrule
A
Iron Bracelet
14
Q
What is the ideal measurement for Ferrule?
A
1.5-2mm
15
Q
W/out ferrule
A
- Greater chance of mechanical failure of restoration (crown)
- all the forces that the crown is subjected to is transferred to the core-→post inside the root
- very tip of post=stress area→root fracture
- Low prognosis
16
Q
What are your 3 options when no ferule effect is present?
A
- Ortho extrusion of the root
- Surgical Crown Lenghtening
- Extract & Implant placement
17
Q
What are the disadvantages of Ortho extrusion of the root due to no ferrule effect
A
- Expense
- More time for treatment
18
Q
What are the disadvantages of Surgical Crown Lengthening due to no ferrule effect
A
- Anterior teeth
- poor esthetics
- “Longer tooth”
- Posterior Teeth
- not possible if furcation exposure is expected
- alter crown/root ratio
19
Q
What are the disadvantages of extraction and implant placement due to no ferrule effect
A
- lose a natural tooth
- implants require more maintenance
20
Q
What is something you should never do to gain ferrule effect?
A
Never Violate Biological Width:
- Subgingival margins-violate biological width
- causes inflammation
- results in recession
- Crown Lengthening should be done when you expect to invade the biological width
21
Q
Classification of posts are based on:
A
- fabrication method
- material
- shape
- presence of threads
22
Q
Posts: Fabrication Method
A
- Prefabricated posts
- Provided as:
- Metallic or non-metallic
- metal
- titanium
- stainless steel
- Non-metal
- fiber
- zirconia
- metal
- Parallel vs tapered
- Threaded vs Non-threaded
- threaded: can be tapped
- non-threaded: only depend on cement for retention
- Serrated vs Smooth
- serrated:better retention
- Metallic or non-metallic
- given a drill system to enlarge and shape canal
- after post is cemented the core is built w/a core material
- amalgam
- composite
- Provided as:
- Cast “Custom” Post & Core
- provided as cartable plastic post pattern
- core is built using wax or pattern resin
- then cast into metal
23
Q
Advantages and Disadvantages of Prefabricated Posts
A
- Advantages:
- ease of use
- less appointments needed
- Disadvantages:
- weak bond b/w the post and core
24
Q
Advantages and Disadvantages of Cast “Custom” Post and core
A
- Advantages:
- core and post are one piece
- minimmizes failures
- Disadvantages
- more expensive
- requires at least 2 appointments
25
Posts based on material
* Metallic Posts:
* Prefabricated
* titanium
* stainless steel
* Cast
* Semiprecious alloy
* Non-metallic posts: Fiber (Fiber Glass) or Zirconia
* Fiber Glass
* flexible post
* same flexibility as dentin
* no root fracture
* Zirconia
* very stiff
* used w/Emax
* pressable ceramic fired to it
26
What are advantages and disadvantages of Metal Posts
* Advantages:
* High strength
* Disadvantages:
* color
* can't use w/full ceramic crowns
27
What are advantages and disadvantages of Non-metallic Posts:
* Advantages:
* Esthetics
* can use w/full ceramic crown
* Disadvantages:
* Fiber-Losses its retention
* its flexibility breaks the cement line
* Zirconia-stiffness
* impossible to retrieve
28
Posts based on shape:
Parallel vs Tapered posts
* no difference in failure loads
* Parallel Posts:
* Prefabricated or Cast posts
* Lower failure rate
* Most failures due to cementation failures
* Tapered Posts:
* Prefabricated or Cast posts
* Higher failure rates
* due to wedging actions
* Most failures due to root fractures
* leave teeth unrestorable
30
What are advantages and disadvantages of non-threaded posts
* Advantages:
* no stress on roots
* Disadvantages:
* less retention
31
What are the advantages and disadvantages of threaded posts:
* Advantages:
* excellent retention
* Disadvantages:
* extreme stress on tooth structures
* leads to root fracture
31
Serrated Posts
* bets of both worlds
* passively fitted to canal
* excellent retention
32
Posts based on presence of thread
ed vs Non-threaded
* Threaded posts:
* tapped into the canal
* Non-threaded posts:
* passively fitted into the canal
* only depend on cement
33
Post Length
* Longer the post the better the:
* retention
* load distribution
* 6mm of apical gutta purcha is preferred
* 3-5mm should be maintained
* \<3mm compromises the apical seal→Leakge→infection
34
Post diameter
* Be conservative
* Thicker the post the thinner the dentin wall that is left
* diameter should be enough to provide stiffness and strength
* Ideal=1.75 mm of sound dentin around entire post
* minimum=1mm
* Increased diameter
* increased strength
* but not retention
35
Post Adaptation:
Adaptation of the post to the canal and the thickness of the resin cement did not affect the retention
36
Luting Agents
* Available: Zinc phosphate, Glass Ionomer, Resin Modified Glass Ionomer, Resin Cement
* Zinc Phosphate & Glass ionomer cements:
* used because of long history of success and ease of manipulation
* Resin Cement:
* less leakage when used w/stainless-steel and carbon fiber posts vs zinc phosphate or glass ionomer cements
37
Core Material
* Amalgam and composite resin core:
* distribute stress to the surface underneath the core
* creates less cervical stress
* Composite cores
* fracture resistance comparable to amalgam and cast post and cores
* but more favorable failure patterns when the fail
